The purpose of this study was to examine the efficacy of a ventilatory training mask to improve anaerobic and aerobic fitness in reserve officers' training corps (ROTC) cadets. Seventeen ROTC cadets from a Midwest university completed pre- and postassessments consisting of anthropometry, a 30-second Wingate Anaerobic Test (WAnT), and a maximal aerobic capacity test (V[Combining Dot Above]O2max). A 6-week intervention training period was used during which time participants completed their mandatory physical training (PT) sessions. Participants were randomly assigned to either the experimental group (MASK; n = 9) or the control group (CON; n = 8). The ventilatory training masks were adjusted to simulate an altitude of 2,750 m. There was no significant effect (p ≤ 0.05) between groups on fatigue index, anaerobic capacity, peak power, V[Combining Dot Above]O2max, or time to exhaustion. These results suggest that the use of the ventilatory training mask during mandatory PT did not elicit superior aerobic or anaerobic adaptations in ROTC cadets. Therefore, it is recommended that more established simulated altitude training methods be used when incorporating intermittent hypoxic training.